The present invention relates to multi-axis tube bending. More particularly, the invention is directed to the dies used in a multi-axis tube bender.
Multi-axis tube benders provide a precise means for continuously bending a curvature into a metal tube as it moves through the bender along an X-axis. Benders generally include a fixed die and a moveable die axially spaced from the fixed die along the X-axis. Each die closely surrounds the exterior cross-section of the tube being bent. A powerful feed mechanism with a pushing tool forces the tube through both dies. As the tube moves through the dies, the moveable die swings through a preprogrammed set of motions relative to the fixed die to bend the tube into a desired curvature.
The fixed die is so-called due to the fact that it is generally rigidly attached to the machine base and its position is only changed during set up of the machine. During set up, the fixed die is positioned to suit the range of radii that will be bent for the specific part to be formed. The moveable die is generally capable of being positioned in two translation directions perpendicular to the direction the tube being bent is moving along the X-axis. A moveable die is generally also capable of rotating about three axial directions.
The axial distance along the X-axis between the fixed die and the moveable die, having been predetermined and locked in during set up of the machine, acts to limit the possible variations in bend radii that can be produced. This distance is a factor in controlling the radius of the bend that is formed in the tube by each movement of the moveable die. Generally, in order to adjust the distance along the X-axis between the two dies, the machine must be taken out of operation and the fixed die relocated. Therefore, the only time the distance between the fixed and moveable die is changed is when an adjustment is being made to run a particular part during machine set up.
It is desirable to provide a machine that is capable of producing a maximum range of bend radii in a part being formed while at the same time providing adequate support for the tube along the X-axis to prevent the tube being formed from buckling or kinking.